Popularity of devices such as tablet computers and smartphones has spawned an ecosystem of software applications utilizing touch input detection, often requiring the detection of multiple touch points simultaneously. The ability to reliably and efficiently detect multi-touch input locations on a display surface has enabled applications to take advantage of new user interface interaction patterns to offer enhanced application usability across a wide range of inexpensive devices. One challenge in multi-touch detection is determination of the number of simultaneous touches or contact points on the sensing surface; such information can be used to simplify and increase the accuracy of determining the touch or contact locations.